• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.3-4
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• 2011

This paper presents a survey of floating power supply based on bootstrap operation for three-level voltage-source inverters. The floating power supply for upper switches is achieved by the bootstrap capacitor charged during on-time of the switch underneath. Hence, a large number of bulky isolated DC/DC power supplies for each gate driver are reduced. The Pspice simulation results show the behavior of bootstrap devices and the performance of bootstrap capacitor voltage.

• Journal of Power Electronics
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• v.7 no.4
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• pp.294-300
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• 2007

This paper deals with a design of a bootstrap power supply using snubber energy regeneration, which is used to power a high-side gate driver of a half-bridge circuit. In the proposed circuit, the energy stored in the low-side snubber capacitor is transferred to the high-side bootstrap capacitor without any magnetic components. Thus, the power dissipation in the RCD snubber can be effectively reduced. The operation principle and design method of the proposed circuit are presented. The experimental results are also provided to show the validity of the proposed circuit.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.2
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• pp.135-144
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• 2008

A bootstrap circuit is widely used for the floating gate power supply of Intelligent power module (IPM). A bootstrap circuit is simple and inexpensive. However, the duty cycle and on-time are limited by the requirement to refresh the charge in the bootstrap capacitor. And the value of the bootstrap capacitor should be increased as the switching frequency decreases. A charge pump circuit can be used to overcome the problems. This paper deals with an analysis and design of a charge pump circuit for the floating gate power supply of an IPM. The simulation and experiment are carried out for an induction motor drive system. The results well verifies the validity of the proposed circuit and design method.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.4
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• pp.376-382
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• 2014

This paper proposes the pulse width modulation (PWM) control strategy for low-speed operation in the three-level neutral-point-clamped (NPC) inverters based on the bootstrap gate drive circuit. As a purpose of the cost reduction, several papers have paid attention to the bootstrap circuit applied to the three-level NPC inverter. However, the bootstrap gate driver IC cannot generate the gate signal to the IGBT for low-speed operation, because the bootstrap capacitor voltage decreases under the threshold level. For low-speed operation, the dipolar and partial-dipolar modulations can be the effective solution. However, these modulations have drawbacks in terms of the switching loss and THD. Therefore, this paper proposes the PWM control strategy to operate the inverter at low-speed and to minimize the switching loss and harmonics. The experimental results are presented to verify the validity on the proposed method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.7
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• pp.563-566
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• 2009

This paper presents a motor drive IC for automotive applications. The drive IC is dedicated to control and drive external MOSFETs which directly drive 3-phase motor with a high current. In case of driving high-side power switches, the bootstrap topology is widely used. however, it requires three bootstrap diode and three capacitor respectively. And it needs a minimum charging time to maintain high-side voltage. The motor drive IC uses a charge-pump circuit for all three high-side voltage with various protection schemes for automotive applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.41-42
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• 2009

This paper presents a motor drive IC for automotive applications. The drive IC is dedicated to control and drive external MOSFETs which directly drive 3-phase motor with a high current. In case of driving high-side power switches, the bootstrap topology is widely used. However, it requires three bootstrap diode and three capacitor respectively. And it needs a minimum charging time to maintain high-side voltage. The motor drive IC uses a charge-pump circuit for all three high-side voltage with various protection schemes for automotive applications.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.421-423
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• 2005

A bootstrap circuit for floating power supply has the advantage of being simple and inexpensive. However, the duty cycle and on-time are limited by the requirement to refresh the charge in the bootstrap capacitor. Hence, this paper deals with a design of charge pump circuit for a floating gate power supply of an IPM. The operation of the proposed circuit applied by three-phase inverter system for driving induction motor are verified through the experiments.

• Journal of IKEEE
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• v.25 no.3
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• pp.517-527
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• 2021

This paper presents the phase-shift full-bridge DC-DC converter using the one-chip micom. The proposed converter primary is the full-bridge power topology that operates with the unipolar pulse-width modulation (PWM) by the phase-shift method, and the secondary is the full-bridge full-wave rectifier composed of four diodes. The control of proposed converter is performed by the one-chip micom and its MOSFET switches are driven by the bootstrap circuit. Thus the total system of proposed converter is simple. The proposed converter achieves high-efficiency using the resonant circuit and blocking capacitor. In this paper, first, the power-circuit operation of proposed converter is explained according to each operation mode. And the power-circuit design method of proposed converter is shown, and the software control algorithm on the micom and the feedback and switch drive circuits operating the proposed converter are described, briefly. Then, the operation characteristics of proposed converter are validated through the experimental results of a designed and implemented prototype converter by the shown design and implementation method in this paper. The highest efficiency in the results was about 92%.